J.M. Newcamp
Please Note
10 records found
1
SmartBasing provides fleet managers tools with which to manage their end-of-life aircraft fleets. The principles of SmartBasing include reassigning aircraft to different bases and assigning aircraft to a new mix of mission types to actively manage the remaining useful lifetime of each aircraft in a fleet. This paper employs a single case study aircraft to validate the SmartBasing approach for a dynamic strategy for aircraft retirement. The United States Air Force’s A-10 Thunderbolt II was used for validation, because it is an aging aircraft fleet that experienced a partial fleet retirement in 2013. The efficacy of the SmartBasing principles was tested using the aircraft retired in 2013 by altering usage patterns and basing locations in the years leading to the 2013 retirement. It was shown that SmartBasing would have been a valid technique for managing the A-10 fleet prior to its partial retirement. Better aircraft utilization planning could have expended more residual aircraft lifetime prior to retirement, resulting in savings of more than 1.88 full aircraft lifetimes or over 83 million USD in aircraft acquisition costs.
Military aircraft retirements are an afterthought for many lifecycle planners. More active management of end-of-life fleets can yield increased confidence in fleet capability and retirement timelines. This work provides fleet managers with a tool to manage remaining aircraft flight hours to yield a desired fleet retirement pattern. It solves an equivalent flight hour minimization problem using a mixed-integer linear programming model for a military aircraft fleet having a network with basing and mission type constraints. The model minimizes differences in remaining equivalent flight hours for individual aircraft in future years, thereby allowing a fleet manager to alter the timeline for retirement of individual aircraft. A relocation cost is applied to discourage excessive, costly aircraft relocations. The United States Air Force A-10 Thunderbolt II aircraft is used as a case study while disruptions such as deployments are modeled to show the methodology's robustness. This work proves that a fleet of aircraft with dissimilar utilization histories and varying amounts of remaining useful lifetime can be actively managed to change the time at which individual aircraft are ready for retirement. The benefit to fleet managers is the ability to extract additional lifetime out of their aircraft prior to retirement.
Control Room Lessons Learned
A Perspective From F-35A Testing
In terms of methodology, in the absence of directly applicable existing research in this field, fleet management concepts and modelling approaches were studied in related fields and then applied to the military fleet retirement problem. The vital first approach to the problem required the baselining of military aircraft fleets given structural loading data and utilization histories. Database analysis and trending algorithms were written to draw correlations between existing data and structural fatigue effects. This work then implemented a greedy algorithm model to solve the individual aircraft retirement scheme. That led to a mixed-integer linear programming approach to optimize a fleet utilization and rotation model. Combined, these methods provided concrete steps for the fleet retirement decision framework, which followed established methods for designing a decision support framework. Throughout the work, a consistent case study fleet (United States Air Force’s A 10 Thunderbolt II) was utilized to provide validation of the methods, while secondary case studies and validation techniques were employed to test applicability of the methods to other military aircraft fleets and other capital asset types.
In terms of concrete research results from the work carried out, this dissertation discovered that a framework for military aircraft fleet retirement decisions was a needed contribution to the field. In the process of building that framework, other valuable results were obtained. It was found that aircraft utilization information could be correlated to cyclic loading data on an individual aircraft level. This revealed patterns in aircraft fleets showing which mission types and basing locations either increased or decreased structural degradation. Using that information led to the result that a fleet manager could determine which aircraft to retire prior to others while optimizing an objective function related to fleet cost, fleet utility or the ratio thereof. It was also found that a fleet manager could selectively utilize individual aircraft at particular bases flying particular missions to prolong or hasten the structural degradation of those aircraft. This led to the result that a fleet manager could therefore forecast retirement dates for an entire fleet, subpopulations within that fleet or individual assets.
From the research carried out, it is emphatically concluded that the results imply that a fleet manager beginning with only aircraft usage data can actively manage a fleet of aircraft to extract residual value from the fleet prior to retirement. This work showed that resource allocation could be improved by utilizing a mixed integer linear program to schedule asset retirements. Further, this work illustrated how a management strategy could impact future usage levels in a way to extend useful lifetime. With a capital asset as critical to national defense and as expensive to acquire, operate and retire as military aircraft, focusing on the end-of-life phase of the systems lifecycle not only promotes forward thinking but also provides potential cost savings. This work’s limitations included its focus on military aircraft instead of all capital assets and that the methods were not implemented in an actual fleet environment. This dissertation demonstrated that a flexible framework with core modelling elements is a tool capable of solving the problem of aircraft fleet retirement decisions. Fleet managers both military and otherwise should investigate the applicability of the methods and findings in this dissertation to their own challenges. Future research must include application of the methods to an actual operating fleet. Also, the methods should be applied to other capital asset classes including military equipment and commercial equipment.
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In terms of methodology, in the absence of directly applicable existing research in this field, fleet management concepts and modelling approaches were studied in related fields and then applied to the military fleet retirement problem. The vital first approach to the problem required the baselining of military aircraft fleets given structural loading data and utilization histories. Database analysis and trending algorithms were written to draw correlations between existing data and structural fatigue effects. This work then implemented a greedy algorithm model to solve the individual aircraft retirement scheme. That led to a mixed-integer linear programming approach to optimize a fleet utilization and rotation model. Combined, these methods provided concrete steps for the fleet retirement decision framework, which followed established methods for designing a decision support framework. Throughout the work, a consistent case study fleet (United States Air Force’s A 10 Thunderbolt II) was utilized to provide validation of the methods, while secondary case studies and validation techniques were employed to test applicability of the methods to other military aircraft fleets and other capital asset types.
In terms of concrete research results from the work carried out, this dissertation discovered that a framework for military aircraft fleet retirement decisions was a needed contribution to the field. In the process of building that framework, other valuable results were obtained. It was found that aircraft utilization information could be correlated to cyclic loading data on an individual aircraft level. This revealed patterns in aircraft fleets showing which mission types and basing locations either increased or decreased structural degradation. Using that information led to the result that a fleet manager could determine which aircraft to retire prior to others while optimizing an objective function related to fleet cost, fleet utility or the ratio thereof. It was also found that a fleet manager could selectively utilize individual aircraft at particular bases flying particular missions to prolong or hasten the structural degradation of those aircraft. This led to the result that a fleet manager could therefore forecast retirement dates for an entire fleet, subpopulations within that fleet or individual assets.
From the research carried out, it is emphatically concluded that the results imply that a fleet manager beginning with only aircraft usage data can actively manage a fleet of aircraft to extract residual value from the fleet prior to retirement. This work showed that resource allocation could be improved by utilizing a mixed integer linear program to schedule asset retirements. Further, this work illustrated how a management strategy could impact future usage levels in a way to extend useful lifetime. With a capital asset as critical to national defense and as expensive to acquire, operate and retire as military aircraft, focusing on the end-of-life phase of the systems lifecycle not only promotes forward thinking but also provides potential cost savings. This work’s limitations included its focus on military aircraft instead of all capital assets and that the methods were not implemented in an actual fleet environment. This dissertation demonstrated that a flexible framework with core modelling elements is a tool capable of solving the problem of aircraft fleet retirement decisions. Fleet managers both military and otherwise should investigate the applicability of the methods and findings in this dissertation to their own challenges. Future research must include application of the methods to an actual operating fleet. Also, the methods should be applied to other capital asset classes including military equipment and commercial equipment.
Time to retire
Indicators for aircraft fleets
Aging Military Aircraft Landscape
A Case for End-of-Life Fleet Optimization